;elves into a state to serve their interests in carrying out func-more efficiently carried out collectively than if they were left f exchange relationships among families through the market, (perfections in the market and imperfections of the decision-nism within the family itself constitute a prime ground for iction. iformation. The case for intervention is strongest with respect n of information. Optimization through private action assumes an act intelligently in their own interest, but information avail-dual families may be erroneous or lacking for the following may falsely assume that society expects them to follow certain vior. Thus the psychic cost attached to defying these imagined /ed if families are informed that no particular demands on their or are imposed from the outside. may be unaware of pertinent information concerning types, ities, and technical and aesthetic properties, etc. of means for ception or terminating pregnancy, or may have incorrect infor-se matters. In either case the resulting decision will necessarily with respect to parenthood are taken under conditions of un-can be lessened if parents are provided with pertinent informa-.1 foresight in regard to the families' future economic prospects, and interests and their appreciation of the dependence of these heir fertility may be more limited than is warranted by the true these matters. imperfections of the "demand" for children also decrease the taining results that will be considered optimal ex post: "pur-Idren are "lumpy" and only moderately repetitive, the learning ' and largely retrospective. Many of the consequences of having only in the long run, and purchases are irreversible, urse, commonplace that prospective parents seek out and ac-information on these matters on their own, and it is clear that rcumstances such information would be reasonably well pro-market or by informal communication. But at least some ele-ptimum informational package would be quasi-collective goods ot be provided, or would be inadequately provided, by profit-•reneurs. Informational messages through the mass media are a . Second, and most important, under backward economic con-arket mechanism may be simply defective in this field, creating mcy argument for collective action.